Machine for automatically filling-inflating gas cushions, notably air cushions, for packaging and use thereof for filling and inflating cushions

ABSTRACT

A machine for automatically inflating air cushions. The cushions have two plastic walls ( 21; 22 ) joined together around their periphery and which thus define a closed space. Said machine comprises a source of gas under pressure, and two jaws ( 1; 2 ) arranged such that they can move on a supporting structure. Each one of said jaws consists of a body ( 1; 3 ) each having a in plane face ( 4:10 ) of substantially the same shape and surface area, it being possible for said faces to mate against one another in order to clamp between them the walls ( 21; 22 ) of a cushion. Each jaw comprises suction means ( 6; 7 ) opening onto its plane face. A first jaw on the inside of its body has a hollow needle ( 5 ) able to move relative to the body and capable in a certain position of having its pointed tip outside of the surface of the plane face. A second jaw within its body has a heating element ( 18 ) able, when the two jaws are clamping between them the two walls of a cushion, of heat-welding the two walls together over a certain proportion of their contacting surface.

The subject of the present invention is a machine for automatically inflating/filling gas cushions, notably air cushions, for packaging, and its use for inflating and filling cushions. Notably to protect delicate and fragile objects against impacts.

Currently, delicate and fragile objects are packaged in cardboard boxes containing particles of expanded polystyrene or shells of expanded polystyrene or other materials. These products generate a large volume of waste which must be destroyed after use. Air-filled cushions are also used for immobilizing objects in the cardboard boxes as a replacement for polystyrene particles. However, the cushions used for immobilizing do not sufficiently protect said objects against impacts. Air cushions have therefore been invented making it possible to surround said objects in one or more air cushions. The latter cushions comprise at least one valve allowing an appropriate inflation, that is to say an inflation of a pressure higher than those previously achieved for immobilization. Document EP 0553027 describes an inflatable cushion of the type defined above.

The inflatable cushions with valves have several drawbacks, notably the valve comprises the risk of leaks and of causing the pressure in the said cushion(s) to reduce, in addition manual inflating takes time.

The objects of the invention are to provide a machine for automatically inflating and filling cushions, notably air cushions, for packaging, and its use for inflating and filling cushions, that is to say a method which requires no human intervention and which does not have the drawbacks of the known methods.

These objects are achieved with the machine for automatically inflating and filling cushions with gas, notably air cushions, for packaging, according to the invention defined in claim 1 and its use defined in claim 4.

The invention will be better understood, its features and its advantages will appear more clearly, on reading the detailed description of forms of execution, given only as an example and made with reference to the appended drawings, in which:

FIG. 1 represents a form of execution of the jaws of a machine according to the invention.

FIG. 2 represents the jaws of FIG. 1 clamping the walls, plastic film, of an uninflated cushion.

FIG. 3 represents the jaws of FIG. 1 during the piercing of the walls.

FIG. 4 represents the jaws of FIG. 1 separated at the time of a first jet of air being used to unstick the two walls of plastic film.

FIG. 5 represents the jaws of FIG. 1 separated, allowing the cushion to be inflated.

FIG. 6 represents the jaws of FIG. 1 separated at the time of inflation of the cushion.

FIG. 7 represents the jaws of FIG. 1 clamping the walls of the inflated cushion.

FIG. 8 represents the jaws of FIG. 1 at the time of the heat-sealing of the walls.

FIG. 9 represents the jaws of FIG. 1 separated at the time of the release of the cushion from the machine.

FIG. 10 represents on a cushion a circular space defined by a discontinuous weld.

FIG. 11 represents a protuberance relating to a particular shape of a cushion.

In all of the figures, the same reference symbols will be used to indicate the same features.

With reference to FIGS. 1 to 9, only the jaws of one machine have been shown, according to a form of execution of the present invention, for the inflation and filling of an air cushion, because all the other elements of the machine are known and within the scope of those skilled in the art. It has also been considered that the two walls of a cushion consist of two sheets of plastic film.

As can be seen in FIG. 1, the two jaws 1 and 2 are mounted on the frame, not shown, of a machine according to the present invention. The jaw 1, mounted movably on the frame of the machine, consists of a cylinder 3, inside which a hollow needle 5 is placed that can move in the direction of the axis of the cylinder 3. Said needle 5 is moved, in the case shown, by a piston 9, but it could also be moved by an electromagnet or any other means. Between the needle 5 and the piston 9 a flexible pipe 8 is provided carrying pressurized air to the inside of the needle 5. The distal end of the needle has a point 15 of which the air outlet is obstructed, while behind the point 15 the needle comprises by two (or a different number) lateral openings 14, designed to inject the air into the cushion (see FIG. 5). The jaw 2 consists of a cylinder 11 retained movably on the frame, not shown. The cylinders 3 and 11 can move longitudinally so that their terminal faces 4 and 10 can come into contact (see FIG. 2). The cylinder 11 contains a cylindrical part 17 concentric with the cylinder 11. Inside said part 17 an electrical heating body 18 is placed powered by an electrical cable 19. At its near end of the cylinder 3 the cylinder 11 has a cavity 16 designed to receive the point 15 of the needle 5. The two ends of the cylinders 3 and 11 face to face have a ring of openings in communication with an aspiration/suction device respectively through aspiration channels 6 and 7 placed in the cylinders 3 and 11.

A use of a machine according to the invention defined in claim 2 proceeds in the following manner:

a) the two walls 21 and 22 of a cushion, uninflated, of any shape, for example square, round, having several pockets connected together, are inserted between the jaws 3 and 11 of the machine as shown in FIG. 1.

b) The two jaws 1 and 2 are moved so as to clamp between their terminal faces 4 and 10 the two sheets of plastic forming the walls of the cushion (see FIG. 2).

c) The needle 5 of the jaw 1 is moved longitudinally perforating the two walls 21 and 22 and placing itself in the cavity 16 of the jaw 2 (see FIG. 3).

d) The two jaws 1 and 2 are moved away slightly and a jet of pressurized air is injected through the lateral openings 14 of the needle 5 so as to unstick the two films 21 and 22 forming the walls of the cushion (see FIG. 4).

e) The two jaws are reclamped, then the aspiration device is activated in the channels 6 and 7, placed in rings about openings allowing the needle to pass, and keep the two walls 21 and 22 stuck to the ends of the cylinders 3 and 11. The pressurized air is injected into the cushion through the openings 14 inflating the latter (see FIGS. 5 and 6).

f) The jaws 1 and 2 are brought together clamping the two walls 21 and 22 between them while compressing the air contained in the cushion (see FIG. 7).

g) The cylinder 17 contained in the body 11 of the jaw 2 is moved so as to press on the periphery of the outlet orifice of the needle 5 of the body 3. The heating element 18 is activated, heat-sealing the two walls along a ring surrounding the hole of the needle 5 preventing the air from leaving the cushion (see FIG. 8).

As can be easily seen in FIG. 8, the surface area of contact between the two jaws 1 and 2 is larger than the heat-sealed zone, therefore, when the jaws are separated to release the cushion from the machine, the zone 23 represents a ring where the two walls are not stuck, and will be separated from one another thus causing a reduction of the pressure in the cushion.

In order to remedy this defect, provision has been made in another form of execution of the use of the machine to provide cushions having at least one location where the two walls are partly heat-sealed defining a space in communication with the rest of the volume included between the two walls. As is seen in FIG. 10, this space is circular, defined by circularly arcuate welds. But this space could have another shape, for example polygonal, square, triangular, the only condition and that the weld line is not continuous so as to remain in communication with the rest of the volume included between the two walls.

FIG. 9 shows the two jaws separated releasing a cushion from the machine, which cushion is inflated according to the last use described above. Note that the heat-sealed zone 27 where the two walls are welded comprises on its periphery a taurus-shaped zone 28 having zones 25, 29 in FIG. 10 where the two walls are welded, the zones 25, respectively 29 (see FIG. 10) are not continuous, hence the inside of the taurus is at the same pressure as the inside 26 of the cushion. In other words, the two walls in the welding zone are able to separate only slightly, which causes only a very slight loss of pressure in the cushion.

In another form of execution of the use of a machine according to the invention, cushions are used that consist of two walls (plastic films) defining a closed space trapping a small quantity of air preventing the two walls from sticking. The latter operation having been carried out previously before entering the machine according to the invention, for example on another machine, known to those skilled in the art. The use proceeds in the following manner:

A) The two walls of a cushion having two walls that are not stuck together are positioned.

B) The two jaws are moved so as to clamp between their terminal faces the two sheets of plastic forming the walls of the cushion.

C) The aspiration device is activated in the channels placed in rings on the terminal faces of the two bodies forming the jaws. The two walls are then kept separated, stuck against said faces.

D) A needle contained in the body of the machine having an opening at its point and moved so as to pierce only the first wall while leaving the other intact.

E) The pressurized air is injected into the cushion inflating the latter.

F) The jaws are brought together clamping the two walls between them while compressing the air contained in the cushion.

G) In the same manner as in the use described above, the cylinder 17 contained in the body 11 of the jaw 2 is moved so as to press on the periphery of the orifice for the needle 5 to exit the body 3. The heating element is activated heat-sealing the two walls along a ring surrounding the hole of the needle preventing the air from leaving the cushion. And the use (method) ends like that previously described with respect to FIG. 9.

In yet another form of execution of a machine according to the invention for inflating cushions, on which a hole has already been made in at least one of the walls, the use will proceed in the following manner:

A) The two walls of a cushion are placed between the jaws so that the hole is placed opposite the outlet orifice of the needle in the face of one of the bodies.

B) The suction device is actuated, the two jaws are separated each keeping one of the walls stuck against them.

D) The pressurized gas is then injected into the cushion through the outlet orifice of the needle provided in the terminal face of one of the jaws without the needle being moved.

The rest of the process then unfolds as described above.

It is also possible to design variants of use in which the cushion is pierced in any location, for example in a corner, or in which the cushion has a protuberance 36 (see FIG. 11) relative to its general shape, the inside 34 of said protuberance being connected to its general volume 36 of said cushion by a duct 33 that will be closed by heat-sealing 37. As can be seen in FIG. 11, a protuberance 36 is attached to the general volume 32 of a cushion by a duct 33, the two films forming the cushion being welded along the line 35.

As can be seen, all the operations described above require no human intervention. Moreover, it is possible to inflate cushions to a higher pressure than by the methods known hitherto. Finally, the piercing can be carried out at any location on the cushion, for example in a corner, in the middle, at an edge, and it is possible to inflate any shape of cushion, even having several pockets communicating with one another. The cushions obtained by a method according to the invention are more inflated, hence more rigid and can, in certain cases, replace the polystyrene shells. The inflation pressure may vary depending on the strength and the thickness of the sheets forming the walls. 

1. A machine for automatically inflating gas cushions, notably air cushions, cushions comprising two walls made of plastic linked together on their periphery, which thus define a closed space, wherein it comprises a source of pressurized gas, two jaws placed movably on a frame, each of said jaws consisting of a body each having a flat face of substantially the same shape and same surface area, said faces being able to come against one another so as to clamp between them the walls of a cushion, each jaw comprising suction means leading onto its flat face, a first jaw having inside its body a hollow needle that can move relative to the body and being able, in a certain position, to have its point outside the surface of the flat face, a second jaw having, inside its body, a heating element which can, when the two jaws clamp between them the two walls of a cushion, heat-seal the two walls together over a certain portion of their contact surface.
 2. The machine as claimed in claim 1, wherein the hollow needle is closed off at its point and has at least one lateral opening close to its point, and is connected at its other end to the source of pressurized gas, that the face of the body comprising the heating element has a cavity designed to receive the point of the needle when the two jaws are clamped, that the periphery of the cavity forms a bearing surface for the heating element so as to make a weld surrounding the needle.
 3. The machine as claimed in claim 1, wherein the hollow needle is open at its point.
 4. The machine as claimed in claim 1, wherein the heating element is made so as to heat-seal the two walls of a cushion along a straight line.
 5. A use of a machine as claimed in claim 2, to inflate cushions, wherein the two walls of a cushion are placed between the jaws of the machine, once said cushion is clamped between the two jaws, the needle is moved so as to pierce the two walls, placing said lateral opening between the walls, pressurized gas is then injected so as to separate the two walls, the two jaws are reclamped, then the suction device is actuated, the two jaws are then separated while each keeping one of the walls stuck against them, the pressurized gas is then injected into the cushion through the lateral opening of the needle of which the point is closed off, finally the two jaws are brought together clamping between them a certain contact surface of the two walls, the heating element is actuated and the two walls are heat-sealed together keeping the cushion inflated when it is released from the jaws.
 6. The use as claimed in claim 5 to inflate cushions, comprising at least one location where the two walls are welded defining a space in communication with the rest of the volume lying between the two walls, wherein the said location is placed between the jaws of the machine; once said cushion is clamped between the two jaws, the needle is moved so as to pierce the two walls in said location, the two jaws are reclamped, then pressurized gas is injected so as to separate the two walls and the suction device is actuated, the two jaws are then separated each keeping one of the walls stuck against them, the pressurized gas is then injected into the cushion through the lateral opening of the needle of which the point is closed off, finally the two jaws are brought together clamping between them a certain surface area of the two walls, the heating element is actuated and the two walls are heat-sealed together keeping the cushion inflated, then the two jaws are moved away releasing the inflated cushion, said location preventing the two walls from separating so as not to reduce the pressure in the cushion when it is released from the jaws.
 7. The use of a machine as claimed in claim 3 to inflate cushions comprising two walls linked together by folds and/or welds, defining a closed space, said space comprising a certain quantity of gas separating said walls, wherein the two walls of a cushion are placed between the jaws of the machine, once said cushion is clamped between the two jaws the suction device is actuated and the two jaws are separated each keeping one of the walls stuck against them, then the needle is moved so as to pierce one of the walls, the pressurized gas is then injected into the cushion through an opening provided at the end of the needle, finally the two jaws are brought together clamping between them a certain surface area of the two walls, the heating element is actuated and the two walls are heat-sealed together keeping the cushion inflated.
 8. The use of a machine as claimed in claim 4 to inflate cushions of polygonal, for example square, shape, wherein a corner of a cushion is placed between the jaws of the machine, once said cushion is clamped between the two jaws the needle is moved so as to pierce the two walls, then the suction device is actuated and the two jaws are separated each keeping one of the walls stuck against them, the pressurized gas is then injected into the cushion through the lateral opening provided on the needle of which the point is closed off, finally the two jaws are brought together clamping between them a certain surface area of the two walls included in the corner, the heating element is actuated and heat-seals the two walls along a line connecting two sides of the corner of said polygon, creating a triangle keeping the cushion inflated.
 9. The use of a machine as claimed in claim 1 to inflate cushions having a hole in one of the walls, wherein the two walls of a cushion are placed between the jaws so that the hole previously made is placed opposite the outlet orifice of the needle in the face of one of the bodies, the suction device is actuated, the two jaws are separated each keeping one of the walls stuck against them, the pressurized gas is then injected into the cushion through a lateral opening provided on the needle or directly through said outlet orifice of the latter of the face of said body, finally the two jaws are brought together clamping between them a certain surface area of the two walls, the heating element is actuated and the two walls are heat-sealed together keeping the cushion inflated.
 10. The use of a machine as claimed in claim 4 to inflate cushions of polygonal shape having a protuberance connected to the rest of the cushion by a duct, wherein the said protuberance is placed between the jaws of the machine, once said protuberance of the cushion is clamped between the two jaws, the needle is moved so as to pierce the two walls, placing said lateral opening between the walls of said protuberance, pressurized gas is then injected so as to separate the two walls, the two jaws are reclamped, then the suction device is actuated, the two jaws are then separated while each keeping one of the walls stuck against them, the pressurized gas is then injected into the cushion through the lateral opening of the needle of which the point is closed off, finally the two jaws are brought together clamping between them a certain surface area of contact of the two walls of the protuberance, the heating element is actuated and the two walls are heat-sealed together along a line closing said duct keeping the cushion inflated when it is released from the jaws. 